In recent years, light emitting diodes (hereinafter, LEDs) have attracted attention because the LEDs consume less power and have longer operating lives than various other light sources. For example, there is proposed a LED light module on which plural LEDs are mounted. In such a LED light module, wiring portions (pads) on which the LEDs are mounted are thick enough to quickly radiate heat generated by the LEDs, as disclosed in, for example, Japanese Laid-open Patent Publication No. 2003-092011 and Japanese Laid-open Patent Publication No. 2006-319074.